• Welcome to MX Bikes Official Forum. Please login or sign up.
 
March 29, 2024, 01:38:57 PM

News:

MX Bikes beta18j available! :)


Parts weight

Started by PiBoSo, February 05, 2015, 05:08:05 PM

Previous topic - Next topic

PiBoSo

Quote from: geofanatec on February 08, 2015, 10:10:49 PM
Lastly, If I had to guesstimate (which I am fairly good at):

Total weight of KTM 350 is 233 lbs or 105.6 kg

If I had to guess:

Front End (tire, forks, triple clamps, handlebars, etc...) around: 48 lbs or 21.8 kg
Middle (seat, fuel tank (empty), engine, frame, footpegs, etc...) around: 123 lbs or 55.7 kg
Rear (rear fender, swingarm, chain, rear tire, etc...) around: 62 lbs or 28.1 kg

This sounds like 12 pounds too much, that should probably be added to the front.

MXK_cdub85

Idk geo, that sounds like a tank to me. My rear swingarm on my 2015 kx450 with linkage, bearings, chain guides/rollers, axle blocks weighs 17.74 lbs. Rear wheel fully assembled with a Dunlop mx52 weighs 28lbs. Subframe/rear fender/air box weighs considerably less then the swingarm. Not quite sure. Those were just weighed as of this afternoon during a tear down.

PiBoSo

February 09, 2015, 01:52:12 AM #17 Last Edit: February 09, 2015, 01:56:09 AM by PiBoSo
Quote from: MXK_cdub85 on February 09, 2015, 01:05:03 AM
Idk geo, that sounds like a tank to me. My rear swingarm on my 2015 kx450 with linkage, bearings, chain guides/rollers, axle blocks weighs 17.74 lbs. Rear wheel fully assembled with a Dunlop mx52 weighs 28lbs. Subframe/rear fender/air box weighs considerably less then the swingarm. Not quite sure. Those were just weighed as of this afternoon during a tear down.

Thank you. Very interesting data.
The swingarm weight is very close to the value currently in MX Bikes beta3: 8kg.
The rear wheel is heavier than expected. Does it include the brake disc and rear sprocket, too, or just rim + tyre?

MXK_cdub85

February 09, 2015, 04:32:29 AM #18 Last Edit: February 09, 2015, 04:47:13 AM by MXK_cdub85
Sorry for the late reply. I noticed I had a mistake.  I re-weighed it just now. The rear wheel assembly, includes a Dunlop MX52 120/80-19, D.I.D dirt star rim 2.15 width , titanium spokes/nipples, aluminum renthal sprocket, titanium axle left in it, Braking steel wave rotor. All of it combined (including Ti Axle) comes to 21.93lbs

I also weighed a spare rear rim, the Same DID dirt star ltx by itself, ie no spokes or hub, it was 6.37lbs. Assembled with only rim, spokes, rub, aluminum rim lock was 8.4lbs.

Dunlop mx52 by itself weighed exactly 12lbs.

Subframe with air box assembly and mudflap was 5.77lbs

Rear fender alone is 1.11 lbs
Front fender alone is 13.16 oz
Front number plate with cable guide is 11.23 oz

Geo, wasn't meaning to offend or dismiss you buddy.
I was under the impression Piboso already had the exhaust and header weight accounted for.

Hope this can be of some help. If you need anything else just ask and I'll do my best.

edit: so as luck would have it, I'm at a friends house right now who owns a 2013 KTM 450SXF. We weighed his front/rear fenders and front number plate.

Front fender no graphics: 13.9oz
Rear fender no graphics: 1.31lbs
Front # plate: 10.9oz

PiBoSo

Quote from: MXK_cdub85 on February 09, 2015, 04:32:29 AM
Sorry for the late reply. I noticed I had a mistake.  I re-weighed it just now. The rear wheel assembly, includes a Dunlop MX52 120/80-19, D.I.D dirt star rim 2.15 width , titanium spokes/nipples, aluminum renthal sprocket, titanium axle left in it, Braking steel wave rotor. All of it combined (including Ti Axle) comes to 21.93lbs

I also weighed a spare rear rim, the Same DID dirt star ltx by itself, ie no spokes or hub, it was 6.37lbs. Assembled with only rim, spokes, rub, aluminum rim lock was 8.4lbs.

Dunlop mx52 by itself weighed exactly 12lbs.

Subframe with air box assembly and mudflap was 5.77lbs

Rear fender alone is 1.11 lbs
Front fender alone is 13.16 oz
Front number plate with cable guide is 11.23 oz

Geo, wasn't meaning to offend or dismiss you buddy.
I was under the impression Piboso already had the exhaust and header weight accounted for.

Hope this can be of some help. If you need anything else just ask and I'll do my best.

edit: so as luck would have it, I'm at a friends house right now who owns a 2013 KTM 450SXF. We weighed his front/rear fenders and front number plate.

Front fender no graphics: 13.9oz
Rear fender no graphics: 1.31lbs
Front # plate: 10.9oz

Thank you very much!
This is gold!
http://www.youtube.com/v/CF7OnW4XDck

Now all is missing is:
- forks
- triple clamps
- front wheel

Anyone?  :P

al167

rear end unsprung mass:
would it be more accurate to just remove the rear shock lower bolt and with the bike on a center stand let the rear wheel drop down onto some scales? this would give actual unsprung mass at point of contact of wheel. allowing for chain, calliper position ect (I can do this if required but my bikes a bit old 2006 crf450r) would be very close still!

for the front forks:
also id assume the lower portion of the fork, fork guards, calliper and axel is counted as unsprung weight? id guess 50% of fork mass for the lower portion. but the forks really need to be disassembled for accurate weighting(sorry not going to do this, maybe someones doing some seals at the moment??). also my forks are the older spring type that are  about1kg heavier than the new psd pneumatic forks that come on most of the bikes from 2013 on (springless).
ill see what I can manage, here too, but I wont be able to do it until the weekend...

wheels
I can see how you need the masses for the wheels for gyroscopic forces. separating masses of hub, tire, rim for calculations may be needed here?

good luck with it piboso!



PiBoSo

Quote from: al167 on February 09, 2015, 01:06:57 PM
wheels
I can see how you need the masses for the wheels for gyroscopic forces. separating masses of hub, tire, rim for calculations may be needed here?

Wheels mass and inertia must be accurate for gyroscopic forces, but also to make the suspensions and jumps work correctly.
Hub, spokes, rim and tire mass can be derived from the total mass, because proportions should be more or less constant.

teeds

Not sure exactly how close this will be or how far off someone might be to tearing down the front end of an actual MX bike, but I have just weighed a set of USD forks/clamps from a road bike. I was looking at the forks on my MX bike for comparison and these seem thicker, but shorter so figured it's pretty similar. They're did have oil in during weighing and came in at 9.3kg, you could take off nearly 1kg if you consider the new type of lighter air forks. HTH
"Damn dirt bikers!" - Bubba

PiBoSo

Quote from: teeds on February 09, 2015, 04:55:27 PM
Not sure exactly how close this will be or how far off someone might be to tearing down the front end of an actual MX bike, but I have just weighed a set of USD forks/clamps from a road bike. I was looking at the forks on my MX bike for comparison and these seem thicker, but shorter so figured it's pretty similar. They're did have oil in during weighing and came in at 9.3kg, you could take off nearly 1kg if you consider the new type of lighter air forks. HTH

Thank you.
Did the forks include springs and dampers?

teeds

Yes the forks are fully working with triple clamps but otherwise stripped, so no callipers or axle etc.
"Damn dirt bikers!" - Bubba

PiBoSo

Quote from: teeds on February 09, 2015, 05:57:56 PM
Yes the forks are fully working with triple clamps but otherwise stripped, so no callipers or axle etc.

What kind of bike is that, just to make a comparison?

motopsycho87

Just remember that manufacturers all lie about weights and powers. Only trust impartial measurements  :)

teeds

Quote from: PiBoSo on February 09, 2015, 06:12:47 PM
Quote from: teeds on February 09, 2015, 05:57:56 PM
Yes the forks are fully working with triple clamps but otherwise stripped, so no callipers or axle etc.

What kind of bike is that, just to make a comparison?

Forks are from a GSXR-750 WW
"Damn dirt bikers!" - Bubba

PiBoSo

Quote from: teeds on February 09, 2015, 06:21:50 PM
Quote from: PiBoSo on February 09, 2015, 06:12:47 PM
Quote from: teeds on February 09, 2015, 05:57:56 PM
Yes the forks are fully working with triple clamps but otherwise stripped, so no callipers or axle etc.

What kind of bike is that, just to make a comparison?

Forks are from a GSXR-750 WW

Thank you very much.
This is an eye opener for GP Bikes, too  :)

Phathry25

Got everything torn down. Then realized I had no way of weighing everything. Might go after a bathroom scale and just hold the stuff while standing on it. Should be close enough, no?